Schema:
Investors (investor_id, Investor_details)
Lots (lot_id, investor_id, lot_details)
Ref_Transaction_Types (transaction_type_code, transaction_type_description)
Transactions (transaction_id, investor_id, transaction_type_code, date_of_transaction, amount_of_transaction, share_count, other_details)
Sales (sales_transaction_id, sales_details)
Purchases (purchase_transaction_id, purchase_details)
Transactions_Lots (transaction_id, lot_id)
Please answer with SQL.